Forty patients suffering from iron deficiency anemia were randomly assigned to receive iron succinylprotein complex (containing 80 mg of elemental iron daily) or iron gluconate complex (containing 125 mg of elemental iron daily) for two months. Improvement, as measured by hematological variables, was noted in both groups, iron succinylprotein complex being superior to iron gluconate complex on some measures. Side effects were reported by two of the 20 patients treated with iron succinylprotein complex and by ten of the 20 patients treated with iron gluconate complex.